Bogen's TWK351 is for situations where there's existing 2-conductor shielded wiring when installing their PI35A or SI35A PA amplifiers. The TWK351 two-wire adapter makes it so that you don't need a three-anunciator call-in signaler.

Bogen's TWK351 is for situations where there's existing 2-conductor shielded wiring when installing their PI35A or SI35A PA amplifiers. The TWK351 two-wire adapter makes it so that you don't need a three-anunciator call-in signaler.